A control apparatus typically controls a controlled object (also referred to as a plant) that is modeled by model parameters. According to a scheme disclosed in Japanese Patent Application Publication No. 2003-15703, an identifier is provided in such a control apparatus to determine a control input through use of model parameters recursively identified by the identifier. Such recursive identification can improve the capability for the control output to follow its desired value.
FIG. 20 shows a functional block diagram of a typical control apparatus. A controlled object 101 is modeled by model parameters. An identifier 102 identifies the model parameters based on a control input and a control output of the controlled object 101. A state predictor 103 considers a dead time, which the controlled object 101 has, to generate a predicted value of the control output by using the model parameters. The predicted value is compared with a desired value. A controller 105 determines the control input into the controlled object 101 so that the predicted value converges to the desired value.